1. Field of the Invention
The invention concerns power transmissions and in particular to modular hydrodynamic coupling units for integration into a power transmission unit.
2. Description of Related Technology
Hydrodynamic couplings with a variety of designs and functions for integration into power transmission units, especially for torque transfer between a driving and a driven shaft, are known. The driving shaft can be coupled, at least indirectly, to a drive unit and the driven shaft can be coupled, at least indirectly, with at least one subassembly to be driven, preferably in the form of a gear.
Hydrodynamic couplings are designed to correspond to their purpose or application. They are used in gears, but furthermore, these couplings also can be used as separate torque-transfer devices in drive lines. In the latter case, the coupling usually has its own housing. Such couplings are known, for example, from Voith publications cr135, cr112 and cr252d. These couplings include at least one primary and one secondary blade wheel, which form at least one toroidal working chamber with one another. In the case of a double-coupling design, two toroidal working chambers are present. The primary wheel and the secondary wheel are then each formed from two blade wheels. The two primary blade wheels are non-rotatingly joined together through a cylindrical intermediate element. Both primary and secondary wheels are usually externally supported. When used in mining, the primary and secondary wheels are internally supported, whenever possible. External support means that the primary wheel is supported on the particular shaft through a hub which can be non-rotatingly connected to the driving shaft and the secondary wheel is supported on the particular shaft through a hub that can be non-rotatingly connected to the driven shaft. The hub itself consists essentially of a sleeve-shaped element, which, in the simplest case, is secured against axial displacement in the axial direction with a screw connection. The hydrodynamic couplings may include a housing, which has two axial end walls. The axial end walls cover at least one part of the extent of the housing in the radial direction. In the built-in position of the hydrodynamic coupling, the hub extends substantially to the region of the axial end walls. Furthermore, such couplings may include means for cooling the operating material during the operation of the hydrodynamic coupling. For this purpose, the heated operating fluid can flow down on the periphery of the primary wheel through nozzles. The heated operating fluid is collected in a dish assigned to the primary wheel. This dish also is non-rotatingly coupled with the primary wheel. A pressure tube, which is oriented against the direction of rotation and penetrates into the dish, takes up the heated operating fluid. The flow energy of the fluid is sufficient to feed it again into the coupling through a cooler. In couplings designed in this way, it is difficult to use the coupling as a complete pre-mounted modular unit in power transmission devices and, furthermore, to provide simple mounting of the components on the driving and driven side. Above all, in designs with two toroidal working chambers (externally or internally supported), there is a need to mount the individual parts of the coupling modular unit one after another.